Write a new Matlab code (Code 6) for the following form of the one-dimensional linear steady-state advection-diffusion equation: U-D=s(x), where s(x) is a known source. dx dx' using the method of Gauss-Seidel successive over-relaxations. a) Re-run the problems shown in Fig. 6.5 in Kundu et al. b) Run the cases in Fig. 6.5 with s(x)=1. Submit the developed code and the plots created. Discuss the results.